#include<bits/stdc++.h>
using namespace std;
#define int long long

int fun(int x) {
	int sum = 0;
	for (int i = 1; i <= x; i++) {
		sum += x * i;
	}
	return sum;
}

signed main() {
	int n;
	cin >> n;
	int ans = 0;
	for (int i = 1; i <= n; i++) {
		ans += fun(i);
	}
	cout << ans;
	return 0;
}
